The original DAS28 formula using erythrocyte sedimentation rate as the inflammatory marker. Used in the majority of historical RA clinical trials and remains the required metric for some biologic prescribing pathways. Runs approximately 0.6 points higher than DAS28-CRP in the same patient.
The DAS28-ESR calculates a composite disease activity score using the 28-joint tender count, 28-joint swollen count, patient global assessment on a 100 mm VAS, and the natural logarithm of ESR. It is the original DAS28 formula developed and validated by Prevow et al. in 1995, and was the primary endpoint in the majority of RA clinical trials from the 1990s through the early 2010s.
The same four activity thresholds apply as for DAS28-CRP (remission below 2.6, low below 3.2, moderate 3.2-5.1, high above 5.1), but the ESR version will consistently produce higher scores in the same patient due to differences in how ESR and CRP behave mathematically in the formula.
Use DAS28-ESR when your institution or health system specifically requires it for a biologic drug approval, insurance authorization, or registry entry. Some European payer systems and older biologic prescribing pathways were validated using DAS28-ESR data and continue to require it. In most clinical settings, DAS28-CRP has become the preferred version for day-to-day monitoring.
Never switch between ESR and CRP versions mid-monitoring without accounting for the approximately 0.6-point systematic difference. A patient who looked like they were in remission on DAS28-ESR and is now being scored with DAS28-CRP may appear to have improved purely due to the formula difference, not actual clinical improvement.
| DAS28-ESR Score | Activity State | Clinical Meaning |
|---|---|---|
| < 2.6 | Remission | Treat-to-target goal. Consider biologic tapering in sustained remission. |
| 2.6 to 3.2 | Low Activity | Acceptable alternative target. Monitor closely. |
| 3.2 to 5.1 | Moderate Activity | Consider therapy adjustment. Most biologic eligibility criteria fall here. |
| > 5.1 | High Activity | Active disease requiring treatment change. |
The DAS28 was developed by Prevow, van 't Hof, Kuper, and colleagues as a simplification of the original 44-joint DAS, published in Arthritis and Rheumatism in 1995. The 28-joint modification was validated in a prospective longitudinal study and demonstrated comparable discriminative ability to the original DAS with significantly reduced assessment burden. The thresholds defining remission below 2.6, low disease activity, moderate, and high activity were validated by van Gestel et al. and formalized by Fransen and van Riel.